1. Field of the Disclosure
The features described herein relate generally to a piezoelectric actuator disposed on a surface of a flow-path forming member of a liquid-droplet ejection head to apply energy to liquid in pressure chambers disposed in the surface, and also relate generally to a liquid-droplet ejection head having the piezoelectric actuator.
2. Description of Related Art
A known liquid-droplet ejection head may include a piezoelectric actuator disposed on a surface of a flow-path forming member (cavity unit). The piezoelectric actuator may be driven to apply energy to ink in pressure chambers disposed in the surface. Ink droplets are ejected from ejection ports of nozzles communicating with the pressure chambers. The piezoelectric actuator include piezoelectric layers (ceramic layers) and electrodes disposed on both surfaces of the piezoelectric layers so as to sandwich the piezoelectric layers in the thickness direction.
A crack may be generated in piezoelectric layers in the process of manufacturing piezoelectric actuators. The crack may be generated in the process of mounting the piezoelectric actuators to flow-path forming members. The crack may be generated in the process of bonding flexible printed circuits (FPCs) to the piezoelectric actuators. The crack generated in the piezoelectric layers may allow ink in the pressure chambers to flow into the crack, causing an electrical short-circuit. The known liquid droplet ejection head include a crack-detecting electrode, which is disposed on the piezoelectric layer positioned at the bottom of the piezoelectric layers included in the piezoelectric actuator. The crack detecting electrode is configured to detect a crack by allowing a current to flow through the crack-detecting electrode.